Just last weekend, had a very strange experience since I was on a code share AZ flight but operated by KLM. At the origin airport, they could not issue the KLM operated leg boarding pass - was told that the systems don't talk to each other and told to get the boarding pass @ FCO upon arrival.
Upon arrival @ FCO, at the AZ transit desk, when I tried to get this, I was sent to go to the KLM transit desk - but I went directly to the gate since the flight was already boarding.
For me - this already shows how bad it is already before all this started - as both ST and (post close working partners), they can't issue boarding passes. I am not sure if this is due to the recent changes in the reservation/booking system of AZ.
Furthermore, at the outstation, with my FB number, there was no recognition of the status (not sure if this is due as indicated in the AZ forum - the changes in the AZ booking/passenger control system).
Cheers!